Luo Hongxin (羅弘信) (836-898), courtesy name Defu (德孚), formally Prince Zhuangsu of Beiping (北平莊肅王), was a warlord in the late Tang dynasty, who controlled Weibo Circuit (魏博, headquartered in modern Handan, Hebei) as its military governor (Jiedushi) after seizing control in 888 after taking advantage of the soldiers' discontent with the prior military governor Le Yanzhen and Le's son Le Congxun (樂從訓). He started a three-generation control by his family over Weibo (with his son Luo Shaowei and grandson Luo Zhouhan), spanning into the post-Tang Later Liang.
Luo Hongxin was from Guixiang (貴鄉), one of the two counties making up the main city of Weibo Circuit's capital Wei Prefecture (魏州). His great-grandfather Luo Xiu (羅秀), grandfather Luo Zhen (羅珍), and father Luo Rang (羅讓) all served as officers at Weibo Circuit. Luo Hongxin himself did so as well from his youth, and he successively served under the military governors Han Jian and Le Yanzhen.
As of spring 888, a tension had developed between the elite headquarters guard corps and Le Yanzhen, over attempts by Le Yanzhen's son Le Congxun to recruit troops to replace the critical role that the headquarters guards played in Weibo's military. At one point, Le Congxun became so fearful of the headquarters guards that he fled from Wei Prefecture; Le Yanzhen subsequently made him the prefect of nearby Xiang Prefecture (in modern Handan) and allowed him to retrieve armors and weapons from Wei Prefecture to equip his own army, which made the headquarters guards even more apprehensive.
Le Yanzhen, sensing the tension and fearing that the headquarters guards were about to mutiny, tried to avoid the mutiny by resigning and becoming a Buddhist monk. The headquarters guards supported the officer Zhao Wenbian (趙文㺹) as acting military governor. Le Congxun, however, had amassed 30,000 troops by this point and tried to contest this succession by marching on Wei Prefecture. Zhao refused to engage Le Congxun in battle, and the soldiers killed him. With there having been a rumor spread around that a god had foretold that Luo would be the new military governor, Luo stepped forward to take the leadership role. He engaged Le Congxun and defeated Le Congxun. Le Congxun withdrew to Neihuang (內黃, in modern Anyang, Henan). Luo put Neihuang under siege.